1-(6-methylpyridin-3-yl)-2-[4-(methylsulfonyl)phenyl]ethanone of formula (I):

having CAS RN 221615-75-4 is an important intermediate for the synthesis of Etoricoxib, which is an active pharmaceutical ingredient belonging to the class of COX-2 inhibitors and has been on the market since 2002 with the trade name Arcoxia.

Examples of use of such compound for the synthesis of COX-2 inhibitors are reported in WO 99/55830, WO 99/15503 and by Davies, Ian W et al. in Journal of Organic Chemistry (2000), 65(25), 8415-8420.
Various multi-step methods for the preparation of such an important building block are known, some of them also reported in patent application EP2497767A1. In the last reference a process is disclosed for the preparation of this intermediate by only one step (or two steps depending on the oxidation state of the sulfur atom) wherein the reaction is performed in absence of water (anhydrous milieu) and employing a least 6 volumes of an organic solvent. This process has the drawback of the relatively “low” productivity due to the relatively large amount of organic solvent employed. An other drawback of this process, observed in industrial scale production, is that a large amount of an inorganic salt is used, such as e.g. tripotassium phosphate anhydrous. This large amount of salt does not allow the starting of the reactor agitator and, however, causes difficulties during the mixing of the reaction mixture.